The present invention relates in general to an apparatus and method for processing soil in a subterranean earth situs; and more particularly, to an improvement over the method and apparatus disclosed in U.S. Pat. No. 5,396,964 dated Mar. 14, 1995. The present invention, among other things, utilizes a single engine, as opposed to the dual engines of U.S. Pat. No. 5,396,964. The single drive engine is used in combination with first and second hydraulic pumps, one pump being used to pressurize slurry for the processing of subterranean soil and the other pump is used to rotate the processing tool.
It is known in the prior art to process soil in a subterranean situs as shown in U.S. Pat. No. 5,396,964. The text of U.S. Pat. No. 5,396,964 is incorporated by reference as though set forth in full herein. The present invention includes several significant improvements over U.S. Pat. No. 5,396,964 and prior art patents referenced and summarized at columns 1 and 2 of that patent.
In particular, the present invention utilizes a single, relatively high horsepower engine carried on the rear of a crane to provide the necessary power for rotating the soil processing tool and to pressurize the slurry which is introduced into the subterranean situs typically along with the soil processing tool. The present invention also provides a programmable, computer operated system for allocating driving power from the single drive engine to optimize the mixing of slurry and soil while simultaneously maximizing the amount of soil being processed. The present invention also provides a leader column provided with guide means and a top drive allowing for the use of multiple sections of cylindrical collar stock, whereas U.S. Pat. No. 5,396,964 required the use of a square Kelly driven by a rotary table. The square Kelly of U.S. Pat. No. 5,396,964 operates without a leader column or guides and typically experiences instability during start-up and operation.
It is therefore a primary object of the present invention to provide an apparatus and method for processing soil in a subterranean situs utilizing power provided by a single engine and allocating that power to pressurize slurry and to drive the soil processing tool in a manner to optimize the mixing of the slurry and soil and to maximize the amount of soil being processed.
Another object of the invention is to provide an apparatus and method for processing soil in a subterranean situs utilizing cylindrical collar stock together with a leader column and guides, resulting in a drive mechanism with greatly increased stability, ease of operation and dependability, all at a reduced cost.
A further object of the invention is to provide a method and apparatus for processing soil in a subterranean situs utilizing a process control system receiving as input variables such as the soil and slurry characteristics of each subterranean situs to determine the appropriate slurry injection pressure while maximizing the amount of soil being processed.
Another object of the invention is to provide an apparatus and method for processing subterranean soil incorporating a pull-down winch responsive to a programmable and computerized process control system to advance a soil processing tool at a rate determined by the process control system.
Yet another object of the invention is to provide a soil processing system utilizing a crane having a single engine carried at the rear of the crane for driving hydraulic pumps for pressurizing slurry and rotating the processing tool and wherein a spotter is carried at the front of the crane to position the leader column and wherein the slurry pump is carried on the spotter.
Further objects and advantages of the invention will become apparent from the following description of a preferred embodiment and the drawings wherein: